Geometric Engineering of Dipolar Interactions in Molecular Tweezer Arrays

Arrays of individually trapped molecules are promising platforms for quantum science due to their long-range dipolar interactions and the extended coherence times available with rotational qubits, which enable dynamic rearrangement of the array geometry during entanglement. We theoretically analyze static geometry tuning and rapid rearrangement as powerful control knobs for dipolar quantum systems, showing that both approaches suppress thermal motional dephasing. Rapid rearrangement can further program interaction patterns dynamically to create many-body entangled states that offer metrological advantages beyond what any fixed geometry can provide. We experimentally implement these geometric control strategies in an array of ultracold CaF molecules, using static three-dimensional geometry tuning to minimize sensitivity to thermal fluctuations and a "geometry echo" protocol to cancel residual dephasing caused by tweezer position fluctuations. Combined with Raman sideband cooling, these techniques lead to a clear enhancement of dipolar interaction coherence. We show that these geometric control approaches unlock both practical performance gains for high-fidelity entanglement generation and open prospects for control of many-body quantum systems.